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Copper sulfate can cause different pathologies in different organ systems during development. We determined the effects of toxic levels of copper sulfate on brain development in term Hubbard broiler chicks using stereological and biochemical analyses. Hubbard broiler chicken eggs were divided into three groups: controls with no treatment, sham-treated animals and an experimental group. On day 1, 0.1 ml saline was injected into the air chambers of the sham and experimental groups. The experimental group received also 50 μg copper sulfate. At term (day 21), all chick brains were removed and their volumes were determined using the Cavalieri volume estimation. Parallel biochemical analyses were carried out for glutathione and malondialdehyde levels in the brain tissues as indicators of oxidative damage. With copper treatment, the mean brain volume (8079 μm3) was significantly decreased compared to both the control (10075 μm3) and sham (9547 μm3) groups. Copper treatment (143.8 nmol/g tissue) showed significantly decreased malondialdehyde levels compared to the control (293.6 nmol/g tissue) and sham groups (268.8 nmol/g tissue). Copper treatment (404.5 nmol/g tissue) showed significantly increased malondialdehyde levels compared to the control (158.6 nmol/g tissue) and sham (142.8 nmol/g tissue) groups. The morphological and biochemical parameters we measured demonstrated that in term Hubbard broiler chicks, toxic levels of copper sulfate cause developmental and oxidative brain damage. 相似文献
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Patterns of ribosomal RNA evolution in salamanders 总被引:4,自引:0,他引:4
Sequence comparisons are presented for four segments of the large subunit
of ribosomal RNA, including divergent domains D7a and D7b, portions of the
large divergent domains D2, D3, and D8, and evolutionarily conservative
sequences flanking divergent domains. These results resolve phylogenetic
relationships among exemplars of seven families of salamanders and the
three amphibian orders. Phylogenetic analysis confirms the prediction that
divergent domains feature the highest relative rates of base substitution
and length variation within the ribosome, but the divergent domains evolve
more slowly than nuclear noncoding DNA and the silent sites of structural
genes. Base substitutions demonstrate approximately twice as many
transitions as transversions and an uneven distribution among sites within
the divergent domains but no apparent bias in base composition. Length
mutations are primarily small insertions and deletions, with deletions
predominating. The divergent domains appear to be a good source of
phylogenetic information for evolutionary events occurring approximately
100-200 million years ago.
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Background
The rapid and accurate identification of species is a critical component of large-scale biodiversity monitoring programs. DNA arrays (micro and macro) and DNA barcodes are two molecular approaches that have recently garnered much attention. Here, we compare these two platforms for identification of an important group, the mammals. 相似文献65.
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Background
In microarray data analysis, factors such as data quality, biological variation, and the increasingly multi-layered nature of more complex biological systems complicates the modelling of regulatory networks that can represent and capture the interactions among genes. We believe that the use of multiple datasets derived from related biological systems leads to more robust models. Therefore, we developed a novel framework for modelling regulatory networks that involves training and evaluation on independent datasets. Our approach includes the following steps: (1) ordering the datasets based on their level of noise and informativeness; (2) selection of a Bayesian classifier with an appropriate level of complexity by evaluation of predictive performance on independent data sets; (3) comparing the different gene selections and the influence of increasing the model complexity; (4) functional analysis of the informative genes. 相似文献67.
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The sugar binding activity of MR60, a mannose-specific shuttling lectin, requires a dimeric state 总被引:1,自引:0,他引:1
MR60 is an intracellular membrane protein which has been shown to act as a
mannoside specific lectin and to be identical to ERGIC-53, a protein
characteristic of the endoplasmic reticulum-Golgi apparatus- intermediate
compartment, acting as a shuttle. According to its primary sequence, this
MR60/ERGIC-53 protein contains a luminal domain including the carbohydrate
recognition domain, a stem, a transmembrane segment and a cytosolic domain.
The endogenous MR60/ERGIC-53 protein is spontaneously oligomeric, (dimers
and hexamers). In this paper, we study the relationship between the
oligomerization state and the sugar binding capacity by using recombinant
proteins. The expression of the recombinant proteins was evidenced by
immunocytochemistry and by immunoprecipitation followed by SDS-PAGE
analysis. The full size recombinant protein binds mannosides and is
oligomeric, up to the hexameric form. Two truncated proteins lacking the
transmembrane and the cytosolic domains were prepared and characterized. A
long one, containing the cysteine 466 close to the C-terminal end of the
recombinant protein but lacking the cysteine 475, close to the C- terminal
end of the native protein, does bind mannosides and forms dimers but no
higher oligomeric forms. A shorter one, lacking both the cysteines 466 and
475, does not bind mannosides and does not form dimers or higher polymers.
The two cysteines in the carbohydrate recognition domain (C190 and C230)
are not involved in the stabilization of oligomers. In conclusion, this
study shows that the luminal moiety of MR60/ERGIC-53 contains a device
allowing both its oligomeric pattern and its sugar binding capability.
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Phylogeny and biogeography of Neotropical spittlebugs (Hemiptera: Cercopidae: Ischnorhininae): revised tribal classification based on morphological data 下载免费PDF全文
ANDRESSA PALADINI DANIELA M. TAKIYA RODNEY R. CAVICHIOLI GERVÁSIO S. CARVALHO 《Systematic Entomology》2015,40(1):82-108
The spittlebug family Cercopidae is currently divided into two subfamilies: the paraphyletic Old World Cercopinae and the monophyletic New World Ischnorhininae. The most recent classification scheme proposed by Fennah in 1968 divided the New World Cercopidae into four tribes: Tomaspidini, Ischnorhinini, Hyboscartini and Neaenini. Herein we present a phylogenetic analysis of Ischnorhininae using 108 morphological characters and including 53 of the 59 recognized genera, to evaluate the tribal‐level classification and understand the processes underlying the current distributional patterns of these genera. We found significant support for the monophyly of many Neotropical genera, but Fennah's tribal classification is revised because tribes Neaenini, Ischnorhinini and Tomaspidini were recovered as polyphyletic. Hyboscartini was synonymized with Tomaspidini. A taxonomic key to tribes and genera of Neotropical spittlebugs is provided based mostly on recovered apomorphies. The biogeographical analysis suggests a Neotropical origin of ischnorhinines, more specifically in northwestern South America. This was possibly coincident spatially and temporally with the origin of grasses, with ancestral range expansions southward to the Amazonian and Paraná regions, and posterior vicariant events, possibly related to the expansion of forests in the Chacoan region, the South America diagonal of open formations. Dispersals to the Chacoan region and to the Nearctic region are hypothesized to have occurred only within genera. In the Chacoan region it is associated with more recent events, such as the diversification of C4 grasses and establishment of the savannas and seasonally dry forests. 相似文献